Mexicans Discover Mutilated Body of Police Officer

Unknown assailants "pulled off the hands, feet, head, legs and arms" of the victim, the state of Chihuahua prosecutor's office said.

Federal police confirmed that the victim was one of their own, raising the toll to 20 federal officers murdered in Ciudad Juarez in 2010 in events linked to drug trafficking.

Police found a message from a drug gang claiming the hit, but did not reveal what the message said.

Separately, four inmates were killed and three other wounded, all with home-made weapons, in a riot in the Ciudad Juarez prison Sunday, officials said.

Police gave no reason for the fight, but local media reported that it was a clash between members of the rival Juarez and Sinaloa drug cartels. More than 200 officers were ordered into the prison to stop the fighting.

Other victims reported over the weekend include three in the border town of Palomas -- their heads were left on benches in the downtown plaza -- three killed in the state capital Chihuahua City, four in Parral, and five shot dead in Ciudad Juarez, police said.

Ciudad Juarez, a city of 1.8 million across the Rio Grande river from El Paso, Texas, is at the epicenter of a wave of drug-related violence that is gripping Mexico.

The Juarez cartel has been waging a bloody war for control of the lucrative trafficking routes into the United States against the Sinaloa cartel, led by Joaquin "El Chapo" Guzman.

Federal police have been deployed to Ciudad Juarez along with thousands of soldiers in an attempt to crack down on all drug traffickers.

Drug violence in Juarez as of late July has led to the deaths of about 7,000 people, compared with 9,000 killed in all of 2009.